Control logix

Are you using an SLC processor with a three position switch, run/program/rem program ?? if so, select rem program, this should fix the problem, just keep in mind, any changes that you make will be online

What do you mean by 'Any Bits' ?
Internal bits? Outputs? which?

I'm guessing you mean internal bits, and yes, they will always stay in their last state. As far as I know, the ControlLogix doesn't have a 'Last Scan' flag. If it did, you could use that programmatically to reset all of your bits.

If it is necessary to clear things on a powerup, use the s:fs flag, or a powerup handler.

If you are looking at physical outputs, you can configure in the I/O configuration how outputs behave in program and fault mode (per point). Each point can be set to 'On', 'Off', or 'Hold'. They should default to off, but may have been set to hold.

Does the CLX line support a Status bit of RUNning ? If so, then you could read that status and display it. We do something like that for the SLC-500 series.Allen: You will find that most PLC's keep internal memory bits at the last state when you switch run->program.

Thanks for you advice guys. It is only internal bits I am talking about.I am communicating to the Citect scada using an ethernet module. The only way I can show external inputs and outputs on the Scada is to use alias tags configured in the CLX. So even if the actual input or output is off in program mode (as they are set to off in the configuration mode) the alias tag still shows an on state. I will try to implement Daves idea about displaying a status bit of running on the Scada to alert the operator of the PLC status.
Thanks Allen